1. Field of the Invention
The present invention relates to an optical-scanning-height measuring device that measures a surface shape of a measurement object.
2. Description of Related Art
An optical-scanning-height measuring device is used to measure a surface shape of a measurement object For example, in a dimension measuring device described in JP-A-2010-43954, light irradiated from a white light source is divided into a measurement light beam and a reference light beam by an optical coupler. The measurement light beam is scanned by a measurement-object scanning optical system and irradiated on any measurement point on the surface of a measurement object. The reference light beam is irradiated on a reference-light scanning optical system. A surface height of the measurement point of the measurement object is calculated on the basis of interference of the measurement light beam and the reference light beam reflected by the measurement object.